Exam Confused Concepts

Question 1

Overflow Error vs. Round-Off Error

Answer 1

• An overflow error results from attempting to display a number that is too large. For example, trying to display a number that requires 4 bits with a program that uses 3 bits is a round-off error.
• A round-off error results from a program’s precision, resulting in a discrepancy between the shown and actual numbers. For example, displaying pi and rounding to 3.14 is considered a round-off error.

Question 2

what’s the difference between INSERT(list, i, value) and APPEND(list, value) in Pseudocode?

Answer 2

• INSERT increases the list size by one, moves all values with a greater position than i one to the right, then adds value to the list at position i.
• APPEND increases the list size by one then adds the value to the end of the list.

Question 3

Do pseudocode lists begin at 0 or 1?

Answer 3

• For the purpose of the AP exam, pseudocode lists begin at 1

Question 4

What forms of data can be represented by binary code?

Answer 4

• Binary code can represent a variety of data forms, from data as simple as strings of characters to images and audio recordings.

Question 5

How do you convert from decimal to hexadecimal? Convert 69 from decimal to hexadecimal.

Answer 5

• Divide the decimal value by 16, then note the quotient and the remainder. Divide the quotient by 16, then note that quotient and remainder. Repeat until you get a quotient of zero. Finally, order your remainders with your first one in the ones place, your second one in the tens place, and so on, replacing any values from 10-15 with their letter correspondents.
• 69 in decimal converts to 45 in hexadecimal.

Question 6

What is Procedural Abstraction?

Answer 6

• Procedural abstraction is the process of breaking down a big problem into smaller increments.